INDIANAPOLIS (WISH) – A former Indiana doctor has been arrested after prosecutors say he gave his patients too much medication, which lead to their deaths

Prosecutors said John Sturman recklessly prescribed medication at Indiana University Hospital.

Sturman worked at the hospital until 2012. Marion County prosecutors said they’ve investigated his four years there and found a disturbing trend.

“Significant quantities of drugs being prescribed without a legit medical purpose from a hospital right here in downtown Indianapolis,” Marion County Deputy Prosecuting Attorney Tim DeLaney said. “It’s unbelievable in many ways.”

During those years, prosecutors say 15 of his patients died within a month of receiving medication. But autopsy results, prosecutors say, were only able to show proof that Sturman caused three deaths.

Prosecutors said Sturman gave the first victim 10 prescriptions over three months. The next victim was given 17 prescriptions over five months.

Finally, prosecutors say Sturman gave one victim 81 prescriptions over a year and a half.

“I would never think somebody that you could trust, like a doctor, would keep prescribing,” Indianapolis resident Joshua Hooten said. “They’re here to help you, not give you something to give you a high off of.”

“I find it very hard to believe because even to become a doctor,” Indianapolis resident Deborah Odwee said, “It takes a lot to get that license and I believe they know what they’re doing, so it’s very hard to believe that they would just dish out medicine.”

Shurman left the hospital three years ago and was investigated at that time, but no charges were ever brought. 24-Hour News 8 asked prosecutors why it took three years to bring charges.

“This was not put on the back burner,” Delaney said. “This was always being investigated diligently. This is a very complex case.”

WISH-TV reached out to Indiana University Hospital officials who said they can’t comment on an active investigation. Sturman also faces 16 counts of issuing invalid prescriptions.

If convicted, he could spend more than 70 years behind bars. Sturman was arrested in Illinois on Friday.

Prosecutors said he was working as a doctor at a Veterans Affairs hospital.